Abstract: Employing a new self-report technique (paging devices), the self-feelings of 35 adolescents were assessed in various naturalistic contexts. Regression analysis was used to assess the stability of self-feelings. Individuals fell into three groups: stable, oscillating, and unpredictable (the largest). For the sample as a whole, self-feelings were not influenced by the immediate context, although specific settings, activities, and others present within the contexts elicited various levels of self-feelings. More crucial for predicting the self-feelings of adolescents are such enduring characteristics as sex, social class, pubertal maturation, stability group, birth order, and number of siblings. The authors argue for a baseline conceptualization of adolescent self-conception from which fluctuations occur.